1. Field of the Invention
The present invention relates to a semiconductor device and a method of fabricating the same. More particularly, the present invention relates to a capacitor structure spaced farthest from a semiconductor substrate and a method of fabricating the same.
2. Description of the Related Art
A semiconductor device may include active elements, e.g., a transistor, a diode, etc., and passive elements, e.g., a resistor, a capacitor, etc. The active elements and the passive elements may be combined to perform original functions of the semiconductor device.
A capacitor may be classified, according to its structure, as a metal-oxide-silicon (MOS) capacitor, a pn-junction capacitor, a polysilicon-insulator-polysilicon (PIP) capacitor, or a metal-insulator-metal (MIM) capacitor. The MOS capacitor, the pn-junction capacitor, and the PIP capacitor may use single crystal or polycrystalline silicon having a higher resistivity than metal as an electrode material in at least one side of the capacitor. The resistances of these capacitor electrodes may thus be relatively larger than that of a MIM capacitor. Additionally, when a voltage is applied to an electrode of the capacitor, a depletion region may be formed on the single crystal silicon or the polycrystalline silicon. Therefore, except for MIM capacitors, it may be difficult to maintain capacitance. As a result, when a high-speed and stable capacitance is required, the MIM capacitor may be widely used in semiconductor devices. For example, the MIM capacitor may be used as, e.g., an analog capacitor or a filter of a wire/wireless communication device, a decoupling capacitor of a main process unit board, a radio frequency (RF) capacitor of a high frequency circuit, etc.
Since most semiconductor capacitors are fabricated using a process for forming interconnection structure, they may be located between a bonding pad and a substrate in a vertical position. However, similar to a RF device, some semiconductor devices need a capacitor structure capable of minimizing the influence caused by a substrate noise, for stabilizing operational characteristics in the semiconductor device.